Siloxane derivatives of amino acids having surface-active properties

ABSTRACT

The present disclosure provides siloxane derivatives of amino acids that have surface-active properties. The amino acid can be naturally-occurring or synthetic, or they may be obtained via a ring-opening reaction of a lactam, such as caprolactam. The amino acid may be functionalized with a siloxane group to form a compound that is surface-active and has surfactant characteristics. The compounds have low critical micelle concentrations (CMC) as well as the ability to lower the surface tension of a liquid.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under Title 35, U.S.C. § 119(e) ofU.S. Provisional Patent Application Ser. No. 62/890,341, filed Aug. 22,2019, entitled SILOXANE DERIVATIVES OF AMINO ACIDS HAVING SURFACE-ACTIVEPROPERTIES, the disclosure of which is incorporated by reference hereinin its entirety.

FIELD

The present disclosure pertains to siloxane derivatives of amino acidsand methods for their synthesis, wherein the siloxane derivatives havesurface-active properties.

BACKGROUND

Surfactants (molecules with surface-active properties) are an importantclass of molecules with highly sought-after characteristics. Surfactantsmay be uncharged, zwitterionic, cationic, or anionic. Often, thesecompounds are amphiphilic molecules with a water-insoluble hydrophobic“tail” group and a water-soluble hydrophilic “head” group. Thesecompounds may adsorb at an interface, such as an interface between twoliquids, a liquid and a gas, or a liquid and a solid. In the case of aninterface between water and oil, the hydrophilic head group extends intothe water, while the hydrophobic tail extends into the oil. When addedto water, the hydrophilic head group extends into the water, while thehydrophobic tail extends into the air. The presence of the surfactantdisrupts the intermolecular interaction between water molecules,replacing it with weaker interactions between water molecules and thesurfactant. This results in lowered surface tension and can also serveto stabilize the interface.

At sufficiently high concentrations, surfactants may form aggregates tolimit the exposure of the hydrophobic tail to the polar solvent. Onesuch aggregate is a micelle, in which the molecules are arranged in asphere with the hydrophobic tails inside the sphere and the hydrophilicheads on the outside to interact with a polar solvent. The effect that agiven compound has on surface tension and the concentration at which itforms micelles may serve as defining characteristics for a surfactant.

Surfactants are widely used in commercial applications in formulationsranging from detergents to hair care products to cosmetics. Compoundswith surface-active properties are used as soaps, detergents,lubricants, wetting agents, foaming agents, and spreading agents, amongothers. Thus, there is an ongoing need to identify and synthesize suchcompounds.

However, solely from its structure, it may be difficult to predictwhether a given compound would have surface-active properties, let aloneother important characteristics such as interfacial adsorption dynamics,minimum surface tension achievable, and/or ability to wet hydrophobicand/or oleophobic surfaces, which are also integral to whether thecompound would become a useful surfactant. Certain amino acids and theirderivatives, for example, are desirable as building blocks forsurfactants, but the selection of which amino acids to use is far fromintuitive. Likewise, some siloxanes are known to possess surface-activeproperties, but again, predicting which siloxane will be effective ishighly challenging. Synthesis of such compounds adds another layer ofdifficulty due to the differences of solubilities attributable todifferent elements and moieties present in the same molecules. Thereremains a need for high-efficacy surfactants that can be readilysynthesized at commercial scale via straightforward routes.

SUMMARY

The present disclosure provides siloxane derivatives of amino acids thathave surface-active properties. The amino acids may be naturallyoccurring or synthetic amino acids, or they may be obtained viaring-opening reactions of molecules such as lactams, for instancecaprolactam. The amino acids may be functionalized with different typesof siloxane groups to form compounds with surface-active properties.Characteristically, these compounds may have low critical micelleconcentrations (CMC) and/or the ability to reduce the surface tension ofa liquid.

The present disclosure provides compounds of Formula I, below:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

n is an integer from 1 to 12;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, hydroxyl,and C₁-C₆ alkyl; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

Further compounds provided by the present disclosure are compounds ofFormula Ia:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

m is an integer from 1 to 6; the terminal nitrogen is optionally furthersubstituted with R³, wherein R³ is selected from the group consisting ofhydrogen, oxygen, and C₁-C₆ alkyl wherein the alkyl chain is optionallysubstituted with one or more substituents selected from the groupconsisting of carboxyl, carboxylate, and sulfonate; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

Additional compounds provided by the present disclosure are compounds ofFormula Ib:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

p is 5;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, and C₁-C₆alkyl, wherein the alkyl chain is optionally substituted with one ormore substituents selected from the group consisting of carboxyl,carboxylate, and sulfonate; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

Still other compounds provided by the present disclosure are thosecompounds of Formula I wherein R¹ and R² are methyl.

Other compounds provided by the present disclosure are compounds ofFormula I, wherein n is 5.

Still other compounds provided by the present disclosure are compoundsof Formula Ib, wherein R¹ and R² are methyl.

Yet other compounds provided by the present disclosure are compounds ofFormula Ib, wherein R³ is hydrogen.

Other compounds provided by the present disclosure are compounds ofFormula Ib wherein the counterion is selected from the group consistingof chloride, bromide, and iodide.

Additional compounds provided by the present disclosure are compounds ofFormula Ib wherein the counterion is chloride.

Other compounds provided by the present disclosure are compounds ofFormula Ib, wherein R³ is methyl.

Other compounds provided by the present disclosure are compounds ofFormula Ib, wherein the counterion is iodide.

Still other compounds provided by the present disclosure are compoundsof Formula Ib, wherein R³ is an oxygen.

Additional compounds provided by the present disclosure are compounds ofFormula Ib, wherein R³ is C₁-C₆ alkyl, substituted with sulfonate.

One specific compound provided by the present disclosure is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexanamide,having the following formula:

A second specific compound provided by the present disclosure is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexaminiumchloride, having the following formula:

A third specific compound provided by the present disclosure is 36-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N,N-trimethyl-6-oxohexan-1-aminiumiodide, having the following formula:

A fourth specific compound provided by the present disclosure is6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-amineoxide, having the following formula:

A fifth specific compound provided by the present disclosure is4-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)butane-1-sulfonate,having the following formula:

A sixth specific compound provided by the present disclosure is5-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)pentane-1-sulfonate,having the following formula:

The above mentioned and other features of the disclosure, and the mannerof attaining them, will become more apparent and will be betterunderstood by reference to the following description of embodimentstaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plot of surface tension versus concentration forSurfactant 2, with a chloride counterion measured at pH=7 as describedin Example 1 b.

FIG. 2 shows a plot of surface tension versus concentration forSurfactant 3 as described in Example 2b.

FIG. 3 shows a plot of dynamic surface tension as change in surfacetension versus time for Surfactant 3 as described in Example 2b.

FIG. 4 shows a plot of surface tension versus concentration forSurfactant 4 as described in Example 3b.

FIG. 5 shows a plot of dynamic surface tension as change in surfacetension versus time for Surfactant 4 as described in Example 3b.

FIG. 6 shows a plot of surface tension versus concentration forSurfactant 5 as described in Example 4b.

FIG. 7 shows a plot of dynamic surface tension as change in surfacetension versus time for Surfactant 5 as described in Example 4b.

DETAILED DESCRIPTION

As used herein, the phrase “within any range defined between any two ofthe foregoing values” literally means that any range may be selectedfrom any two of the values listed prior to such phrase regardless ofwhether the values are in the lower part of the listing or in the higherpart of the listing. For example, a pair of values may be selected fromtwo lower values, two higher values, or a lower value and a highervalue.

As used herein, the word “alkyl” means any saturated carbon chain, whichmay be a straight or branched chain.

As used herein, the phrase “surface-active” means that the associatedcompound is able to lower the surface tension of the medium in which itis dissolved, and/or the interfacial tension with other phases, and,accordingly, may be adsorbed at the liquid/vapor and/or otherinterfaces. The term “surfactant” may be applied to such a compound.

With respect terminology of inexactitude, the terms “about” and“approximately” may be used, interchangeably, to refer to a measurementthat includes the stated measurement and that also includes anymeasurements that are reasonably close to the stated measurement.Measurements that are reasonably close to the stated measurement deviatefrom the stated measurement by a reasonably small amount as understoodand readily ascertained by individuals having ordinary skill in therelevant arts. Such deviations may be attributable to measurement erroror minor adjustments made to optimize performance, for example. In theevent it is determined that individuals having ordinary skill in therelevant arts would not readily ascertain values for such reasonablysmall differences, the terms “about” and “approximately” can beunderstood to mean plus or minus 10% of the stated value.

The present disclosure provides siloxane derivatives of amino acids. Theamino acids may be naturally occurring or synthetic, or they may beobtained from ring-opening reactions of lactams, such as caprolactam.The compounds of the present disclosure have been shown to havesurface-active properties, and may be used as surfactants and wettingagents, for example. In particular, the present disclosure providescompounds of Formula I, shown below:

wherein R¹ and R² may be the same or different, and are at least onegroup selected from the group consisting of C₁-C₆ alkyl, optionally theC₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfur atomsor substituents that include one or more of these atoms, the alkyl chainmay be optionally substituted with one or more substituents selectedfrom the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

n is an integer from 1 to 12;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, hydroxyl,and C₁-C₆ alkyl; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

The present disclosure further provides for compounds of Formula Ia:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

m is an integer from 1 to 6;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, and C₁-C₆alkyl wherein the alkyl chain is optionally substituted with one or moresubstituents selected from the group consisting of carboxyl,carboxylate, and sulfonate; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

The present disclosure additionally provides for compounds of FormulaIb:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

p is 5;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, and C₁-C₆alkyl, wherein the alkyl chain is optionally substituted with one ormore substituents selected from the group consisting of carboxyl,carboxylate, and sulfonate; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

One specific compound provided by the present disclosure is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexanamide(Surfactant 1), having the following formula:

A second specific compound provided by the present disclosure is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexaminiumchloride (Surfactant 2), having the following formula:

A third specific compound provided by the present disclosure is 36-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N,N-trimethyl-6-oxohexan-1-aminiumiodide (Surfactant 3), having the following formula:

A fourth specific compound provided by the present disclosure is6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-amineoxide (Surfactant 4), having the following formula:

In the structure above, the notation “N→O” is intended to convey anon-ionic bonding interaction between nitrogen and oxygen.

A fifth specific compound provided by the present disclosure is4-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)butane-1-sulfonate(Surfactant 5), having the following formula:

A sixth specific compound provided by the present disclosure is5-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)pentane-1-sulfonate,having the following formula:

These compounds may be synthesized by various methods. One such methodincludes reacting an amino acid, such as an N-alkylated or N-acylatedamino acid, with a siloxane to convert the amino acid C-terminus to thedesired siloxane derivative. The amino acid N-terminus may be furtherprotonated, alkylated, or oxidized to yield a quaternary amine or anN-oxide, for example.

The amino acid may be naturally occurring or synthetic or may be derivedfrom a ring opening reaction of a lactam, such as caprolactam. Thering-opening reaction may be either an acid or alkali catalyzedreaction, and an example of an acid catalyzed reaction is shown below inScheme 1.

The amino acid may have as few as 1 or as many as 12 carbons between theN- and C-termini. The alkyl chain may be branched or straight. The alkylchain may be interrupted with nitrogen, oxygen, or sulfur. The alkylchain may be further substituted with one or more substituents selectedfrom the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carboxyl, and carboxylate. The N-terminal nitrogen may beacylated or alkylated with one or more alkyl groups. For example, theamino acid may be 6-(dimethylamino)hexanoic acid.

The siloxane may be substituted with one or more alkoxy groups, such asmethoxy, ethoxy, isopropoxy, tertiary butoxy, and others. The siloxanemay be further substituted with one or more alkyl groups, such aspropyl, wherein the alkyl group may yet be further substituted with anappropriate functional group to permit coupling of the siloxane to theamino acid, such as a nitrogen. For example, the siloxane may be3-aminopropyltris(trimethylsiloxy)silane.

The siloxane derivative of the amino acid may be synthesized as shownbelow in Scheme 2. As shown, 6-aminohexanoic acid is treated withformaldehyde in formic acid at reflux to give 6-(dimethylamino)hexanoicacid. The free carboxylic acid is then coupled to3-aminopropyl(trismethylsiloxy)silane in refluxing toluene to give thedesired siloxane derivative.

The N-terminal nitrogen may be further derivatized to modify or improvewater solubility and surface-active properties. A sample syntheticscheme is shown below in Scheme 3, in which the N-terminal nitrogen istreated with hydrochloric acid to give the corresponding hydrochloridesalt.

The N-terminal nitrogen may be alkylated. A sample synthetic scheme isshown below, in which the N-terminal nitrogen is treated with methyliodide to give the corresponding quaternary amine salt.

The N-terminal nitrogen may be treated with hydrogen peroxide in waterat reflux to give the corresponding N-oxide, as shown in the samplesynthetic scheme below, Scheme 5.

The compounds of the present disclosure demonstrate surface-activeproperties. These properties may be measured and described by variousmethods. One method by which surfactants may be described is by themolecule's critical micelle concentration (CMC). CMC may be defined asthe concentration of a surfactant at which micelles form, and abovewhich all additional surfactant is incorporated into micelles.

As surfactant concentration increases, surface tension decreases. Oncethe surface is completely overlaid with surfactant molecules, micellesbegin to form. This point represents the CMC, as well as the minimumsurface tension. Further addition of surfactant will not further affectthe surface tension. CMC may therefore be measured by observing thechange in surface tension as a function of surfactant concentration. Onesuch method for measuring this value is the Wilhemy plate method. AWilhelmy plate is usually a thin iridium-platinum plate attached to abalance by a wire and placed perpendicularly to the air-liquidinterface. The balance is used to measure the force exerted on the plateby wetting. This value is then used to calculate the surface tension (γ)according to Equation 1:γ=F/I cos θ  Equation 1:wherein I is equal to the wetted perimeter (2w+2d, in which w and d arethe plate thickness and width, respectively) and cos θ, the contactangle between the liquid and the plate, is assumed to be 0 in theabsence of an extant literature value.

Another parameter used to assess the performance of surfactants isdynamic surface tension. The dynamic surface tension is the value of thesurface tension for a particular surface or interface age. In the caseof liquids with added surfactants, this can differ from the equilibriumvalue. Immediately after a surface is produced, the surface tension isequal to that of the pure liquid. As described above, surfactants reducesurface tension; therefore, the surface tension drops until anequilibrium value is reached. The time required for equilibrium to bereached depends on the diffusion rate and the adsorption rate of thesurfactant.

One method by which dynamic surface tension is measured relies upon abubble pressure tensiometer. This device measures the maximum internalpressure of a gas bubble that is formed in a liquid by means of acapillary. The measured value corresponds to the surface tension at acertain surface age, the time from the start of the bubble formation tothe occurrence of the pressure maximum. The dependence of surfacetension on surface age can be measured by varying the speed at whichbubbles are produced.

Surface-active compounds may also be assessed by their wetting abilityon solid substrates as measured by the contact angle. When a liquiddroplet comes in contact with a solid surface in a third medium, such asair, a three-phase line forms among the liquid, the gas and the solid.The angle between the surface tension unit vector, acting at thethree-phase line and tangent at the liquid droplet, and the surface isdescribed as the contact angle. The contact angle (also known as wettingangle) is a measure of the wettability of a solid by a liquid. In thecase of complete wetting, the liquid is completely spread over the solidand the contact angle is 0°. Wetting properties are typically measuredfor a given compound at the concentration of 1-10× CMC, however, it isnot a property that is concentration-dependent therefore measurements ofwetting properties can be measured at concentrations that are higher orlower.

In one method, an optical contact angle goniometer may be used tomeasure the contact angle. This device uses a digital camera andsoftware to extract the contact angle by analyze the contour shape of asessile droplet of liquid on a surface.

Potential applications for the surface-active compounds of the presentdisclosure include formulations for use as shampoos, hair conditioners,detergents, spot-free rinsing solutions, floor and carpet cleaners,cleaning agents for graffiti removal, wetting agents for cropprotection, adjuvants for crop protection, and wetting agents foraerosol spray coatings.

It will be understood by one skilled in the art that small differencesbetween compounds may lead to substantially different surfactantproperties, such that different compounds may be used with differentsubstrates, in different applications.

The following non-limiting embodiments are provided to demonstrate thedifferent properties of the different surfactants. In Table 1 below,short names for the surfactants are correlated with their correspondingchemical structures.

TABLE 1 Surfactant Formula & Name Surfactant 1

6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexanamide Surfactant 2

6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-aminium chloride Surfactant 3

6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N,N-trimethyl-6-oxohexan-1-aminium iodide Surfactant 4

6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-amine oxide Surfactant 5

4-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)butane-1-sulfonate

Each of the five compounds are effective as surface-active agents,useful for wetting or foaming agents, dispersants, emulsifiers, anddetergents, among other applications.

Surfactants 1 and 2 candidates for use in a variety of surface cleaningand personal care product formulations as foaming or wetting agents.

Surfactant 3 is cationic. These surfactants are useful in both theapplications described above and some further special applications suchas surface treatments, such as in personal hair care products, and canalso be used to generate water repellant surfaces.

Surfactant 4 is non-ionic, and can be used in shampoos, detergents, hardsurface cleaners, and a variety of other surface cleaning formulations.

Surfactant 5 is zwitterionic. These surfactants are useful asco-surfactants in all of the applications described above.

The amount of the compounds disclosed herein used in a formulation maybe as low as about 0.001 wt. %, about 0.05 wt. %, about 0.1 wt. %, about0.5 wt. %, about 1 wt. %, about 2 wt. %, or about 5 wt. %, or as high asabout 8 wt. %, about 10 wt. %, about 15 wt. %, about 20 wt. %, or about25 wt. %, or within any range defined between any two of the foregoingvalues.

EXAMPLES

Nuclear magnetic resonance (NMR) spectroscopy was performed on a Bruker500 MHz spectrometer. The critical micelle concentration (CMC) wasdetermined by the Wilhelmy plate method at 23° C. with a tensiometer(DCAT 11, DataPhysics Instruments GmbH) equipped with a Pt-Ir plate.Dynamic surface tension was determined with a bubble pressuretensiometer (Krüss BP100, Krüss GmbH), at 23° C. Contact angle wasdetermined with the optical contact angle goniometer (OCA 15 Pro,DataPhysics GmbH) equipped with a digital camera.

Example 1a Synthesis of6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexanamide(Surfactant 1) and6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-aminiumsalt (Surfactant 2)

6-(Dimethylamino)hexanoic acid (2.00 g, 12.56 mmol, 1 equiv.) wasdissolved in toluene (50 mL) in a 100 mL round bottom boiling flaskequipped with a Dean Stark trap, then3-aminopropyltris(trimethylsiloxy)silane (5.48 mL, 13.81 mmol, 1.1equiv.) was added. The reaction vessel was heated, and the reactionrefluxed for 24 hours until no more water separated in the Dean Starktube. The solvent was removed under vacuum to give Surfactant 1 as ayellow oil in 94% yield. ¹H NMR (500 MHz, DMSO) δ: 0.09 (s, 27H),0.28-0.31 (m, 2H), 1.12-1.26 (m, 2H), 1.27-1.30 (m, 4H), 1.38-1.41 (m,2H), 1.94 (t, J=7.3 Hz, 2H), 2.00 (s, 6H), 2.06-2.03 (m, 2H), 2.89 (dd,J=12.9, 6.8 Hz, 2H).

In its neutral form, Surfactant 1 is slightly soluble in pure waterwithout addition of hydrotropes or other surfactants, but afterprotonation in slightly acidic conditions it becomes interfaciallyactive (Surfactant 2). The acidic conditions can be generated by theaddition of any acid or acidic buffer in the pH range of 4-7. Surfactant2 can also be prepared in non-aqueous solutions, for example by sparginggaseous HCl in toluene in the presence of Surfactant 1.

Example 1 b Determination of Critical Micelle Concentration (CMC) ofSurfactant 2

The critical micelle concentration (CMC) for Surfactant 2 was testedwith a chloride counterion and was determined to be about 2 mmol. Theplateau value of minimum surface tension that can be reached by thissurfactant is about 23 mN/m. FIG. 1 is a plot of these results, showingsurface tension versus concentration.

Example 2a Synthesis of6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N,N-trimethyl-6-oxohexan-1-aminiumiodide (Surfactant 3)

Surfactant 1 (1.00 g, 2.02 mmol, 1 equiv.) was dissolved in acetonitrile(10 mL) in a 100 mL round bottom flask. Next, Na₂CO₃ (0.26 g, 2.42 mmol,1.2 equiv.) was added and the mixture was stirred for 10 minutes. Methyliodide (0.377 mL, 6.06 mmol, 3 equiv.) was added and the reaction washeated at 40° C. for 24 hours. The cooled reaction mixture was filtered,and the solvent was removed under vacuum to give Surfactant 3 as aslightly yellow solid in quantitative yield. ⁻H NMR (500 MHz, DMSO) δ0.09 (s, 27H), 0.38-0.42 (m, 2H), 1.23-1.26 (m, 2H), 1.37-1.40 (m, 2H),1.52-1.55 (m, 2H), 1.65-1.69 (m, 2H), 2.08 (t, J=7.4 Hz, 2H), 2.99 (dd,J=13, 6.9 Hz, 2H), 3.04 (s, 9H),), 3.24-3.33 (m, 2H).

The pure product is soluble in water and has surfactant properties. Thehalogen anions may be directly obtained from the N-alkylation reaction,and other desired counter anions may be obtained by anion exchange.

Example 2b Determination of Physical Properties of Surfactant 3

The critical micelle concentration (CMC) for Surfactant 3 was measured.From the surface tension change with concentration in water, the CMC wasdetermined to be about 1.6 mmol. The plateau value of minimum surfacetension that can be reached by this surfactant is around 20 mN/m,indicating that the surfactant has outstanding interfacial activity.These results are plotted as surface tension versus concentration inFIG. 2.

The dynamic surface tension of Surfactant 3 was determined with a bubblepressure tensiometer which measures the change of surface tension of afreshly created air-water interface with time. FIG. 3 shows a plot ofthe results as surface tension versus time and demonstrates thatSurfactant 3 fully saturated the interface in less than 500 ms, makingit exceptionally fast in terms of interfacial adsorption.

In addition to Surfactant 3's ability to lower both interfacial andsurface tension, formulations containing only Surfactant haveexceptional wetting properties. For example, hydrophobic substrates suchas polyethylene and polypropylene exhibit a total surface wetting with acontact angle of 0°. On oleophobic and hydrophobic substrates such asTeflon, the measured contact angle was extremely low, 10.5° (Table 2).

TABLE 2 CA of CA of Substrate Surfactant 3 (°) Concentration water (°)Teflon 10.5 10 × CMC 119 Polyethylene 0 10 × CMC 91.5 Polypropylene 0 10× CMC 93.3 Nylon 0 10 × CMC 50 Polyethylene terephthalate 0 10 × CMC65.3

Example 3a Synthesis of6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-amineoxide (Surfactant 4)

Surfactant 1 (1.00 g, 2.02 mmol, 1 equiv.) was added to distilled water(80 mL) in a 100 mL round bottom flask, followed by 50% hydrogenperoxide (1.15 mL, 20.2 mmol, 10 equiv.). The reaction was refluxed for12 hours, then concentrated under vacuum. The residue was washed threetimes with acetone to give Surfactant 4 in 99% yield. ¹H NMR (500 MHz,DMSO) δ 0.09 (s, 27H), 0.38-0.44 (m, 2H), 1.21-1.25 (m, 2H), 1.35-1.42(m, 2H), 1.50-1.55 (m, 2H), 1.71-1.75 (m, 2H), 2.05-2.08 (m, 2H),2.97-3.00 (m, 2H), 3.01 (s, 9H), 3.11-3.14 (m, 2H).

Example 3b Determination of Physical Properties of Surfactant 4

The critical micelle concentration (CMC) for Surfactant 4 was measured.From the surface tension change with concentration in water, the CMC wasdetermined to be about 0.49 mmol. The plateau value of minimum surfacetension that can be reached by this surfactant is about 20 mN/m,indicating that the surfactant has outstanding interfacial activity.These results are plotted as surface tension versus concentration inFIG. 4.

The dynamic surface tension of Surfactant 4 was determined with a bubblepressure tensiometer. FIG. 5 shows a plot of the results as surfacetension versus time and demonstrates that Surfactant 4 fully saturated afreshly created air-water interface in one second or less, making itfast in terms of interfacial adsorption.

In addition to Surfactant 4's ability to lower both the interfacial andsurface tension, formulations containing only Surfactant 4 inconcentrations of 1-100×CMC have exceptional wetting properties. Forexample, a solution of Surfactant 4 in water at a concentration of10×CMC exhibits a 0° contact angle on hydrophobic substrates such aspolyethylene and polypropylene, and 10.6° on oleophobic and hydrophobicsubstrates such as Teflon. These contact angles are extremely low incomparison with the contact angle of water on the same substrate (Table3).

TABLE 3 CA of CA of Substrate Surfactant 4 (°) Concentration water (°)Teflon 10.6 10 × CMC 119 Polyethylene 0 10 × CMC 91.5 Polypropylene 0 10× CMC 93.3 Nylon 0 10 × CMC 50 Polyethylene terephthalate 0 10 × CMC65.3

Example 4a Synthesis of4-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)butane-1-sulfonate(Surfactant 5)

Surfactant 1 (1.00 g, 2.02 mmol, 1 equiv.) was added to ethyl acetate(EtOAc) (30 mL) in a 100 mL round bottom flask, followed by 1,2-butanesultone (0.27 mL, 2.2 mmol, 1.1 equiv.). The reaction was refluxed for12 hours, after which the solvent was removed and the resultant whitewaxy solid was washed with acetone to give Surfactant 5 in 50% yield. ¹HNMR (500 MHz, DMSO) δ 0.10 (s, 27H), 0.38-0.46 (m, 2H), 1.23-1.27 (m,2H), 1.37-1.68 (m, 10H), 1.73-1.78 (m, 2H), 2.45-2.48 (m, 2H), 2.97-3.01(m, 8H), 3.18-3.21 (m, 2H), 3.23-3.27 (m, 2H).

Example 4b Determination of Physical Properties of Surfactant 5

The critical micelle concentration (CMC) for Surfactant 5 was measured.From the surface tension change with concentration in water, the CMC wasdetermined to be about 0.39 mmol. The plateau value of minimum surfacetension that can be reached by this surfactant is about 21 mN/m,indicating that the surfactant has outstanding interfacial activity.These results are plotted as surface tension versus concentration inFIG. 6.

The dynamic surface tension of Surfactant 5 was determined with a bubblepressure tensiometer. FIG. 7 shows a plot of the results as surfacetension versus time and demonstrates that Surfactant 5 fully saturated afreshly created air-water interface in one second or less, making itfast in terms of interfacial adsorption.

Finally, a solution of Surfactant 5 in water at a concentration of10×CMC exhibits a 0° contact angle on hydrophobic substrates such aspolyethylene and polypropylene, and 10.2° on oleophobic and hydrophobicsubstrates such as Teflon. These contact angles are extremely low incomparison with the contact angle of water on the same substrate (Table4).

TABLE 4 CA of CA of Substrate Surfactant 5 (°) Concentration water (°)Teflon 10.2 10 × CMC 119 Polyethylene 0 10 × CMC 91.5 Polypropylene 0 10× CMC 93.3 Polyethylenterephthalate 0 10 × CMC 65.3 Nylon 0 10 × CMC 50Polyethylene-HD 0 10 × CMC 93.6

Example 5 Formulation for Shampoo

In this Example, a formulation for use as a shampoo is provided. Thisformulation is useful in in providing hair with a smooth and silky feel.The components of the formulation are shown below in Table 4.Additionally, the formulation may include other natural oils andingredients, as well as vitamins for consumer appeal, in an amount ofless than 1 wt. %.

TABLE 4 Component Function Weight % Surfactant 5 Surfactant 0.1-10 Ammonium lauryl sulfate Foaming agent 10-25 Cocamidopropyl betaineCo-surfactant 0.1-5   Cocamide diethanolamine Foam booster 1-4 Xantangum or Thickener/ 0-5 acrylate copolymer rheology modifier Citric acidpH stabilizer 0.1-0.3 Fragrance 0.02-0.1  Water 49.5-89  

Example 6 Formulation for Hair Conditioner

In this Example, a formulation for use as a hair conditioner isprovided. This formulation may be used to replace or reducepolyquaternium-10, polyquaternium-7 and dimethicone oils, whilepreserving the easy combability and silky-soft feel that hairconditioners provide. The formulation is shown below in Table 5.

TABLE 5 Component Function Weight % Surfactant 3 Surfactant  1-10Surfactant 5 Surfactant 0.1-10  Sodium cumene sulfonate Hydrotrope 1-3Ammonium lauryl sulfate Surfactant 0.1-6   Ammonium laureth-3 sulfateSurfactant 0.1-6   Cocoamide diethanolamine Foaming agent 0.5-2   PEG-55propylene glycol oleate Emulsifier 0.01-1   Fragrance 0.02-0.1  Water61.9-97.2

Example 7 Formulation for Car Washing Detergents for Removal ofDifficult Spots from the Surface

In this Example, a formulation for use car washing detergents forremoval of difficult spots from the surface is provided. The formulationis shown below in Table 6.

TABLE 6 Component Function Weight % Surfactant 5 Surfactant 0.1-10 Dodecyl benzene sulfonic acid Foaming/  5-14 or Ammonium lauryl sulfatedetersive agent Monoethanolamine, pH stabilizer <0.5 diethanolamine, ortriethanolamine Cocoamide diethanolamine Foam stabilizer 0.1-2  Propylene glycol Solubilizing agent 0.05-1.6  Fragrance 0.02-0.1 Coloring agent   0-0.1 Water 71.6-95.0

Example 8 Formulation for a Spot-Free Rinsing or Drying Solution

In this Example, a formulation a spot-free rinsing or drying solution isprovided. The solution may be applied to the windows or body of a carafter the main wash is complete. The formulation is shown below in Table7.

TABLE 7 Component Function Weight % Surfactant 5 Surfactant 0.001-2   Water    98-99.999

Example 9 Formulation for a Heavy-Duty Carpet Cleaner

In this Example, a formulation for a heavy-duty carpet cleaner isprovided. The cleaner is a high-foaming deep cleaner. The formulation isshown below in Table 8.

TABLE 8 Component Function Weight % Surfactant 4 Surfactant  1-15Dodecyl benzene sulfonic acid Foaming/ or Ammonium lauryl sulfatedetersive agent 0.001-10   Sodium cumene sulfonate Hydrotrope 0.001-3   Monoethanolamine, diethanolamine, or triethanolamine pH stabilizer0.01-1   Water 74.95-99  

Example 10 Formulation for a Heavy-Duty Surface Cleaner

In this Example, a formulation for a heavy-duty surface cleaner isprovided. This cleaner may be used for manual or automated surfacecleaning machines. The formulation is shown below in Table 9.

TABLE 9 Component Function Weight % Surfactant 4 Surfactant 0.001-25  Dodecyl benzene sulfonic acid Foaming/ 0.001-10   or Ammonium laurylsulfate detersive agent Sodium cumene sulfonate Hydrotrope <0.5Propylene glycol Solubilizing agent 0.01-5   Water  59.5-99.99

Example 11 Formulation for a Concentrated Graffiti Removal Detergent

In this Example, a formulation for a concentrated graffiti removaldetergent is provided. The detergent may be used in a high-pressurehose. The formulation is shown below in Table 10.

TABLE 10 Component Function Weight % Surfactant 4 Surfactant 0.001-15  Surfactant 5 Co-wetting agent 0.001-10   Sodium cumene sulfonateHydrotrope 0.001-3    Propylene glycol Solubilizing agent 0.01-5   Water  67-99.99

Example 12 Formulation for a Wetting Agent in Aerosol Sprays

In this Example, a formulation for a wetting agent adjuvant in aerosolsprays is provided. The aerosol sprays may be used to apply pesticidesor other crop protecting agents. The provided formulation aims to reducethe amount of surfactant chemicals in pesticide and crop protection(typically between 2-5%) by providing better performance throughexcellent wetting and low CMC, thus providing a greener option. Theformulation is shown below in Table 11.

TABLE 11 Component Function Weight % Surfactant 2, 4, 0r5 Co-wettingagent 0.001-2    Pesticide and/or other 0.1-10  crop protection agent(s)Water    88-99.899

Example 13 Formulation of Additives for Aerosol Spray Paint

In this Example, a formulation for an additive for a water-based aerosolspray paint or coating is provided. The formulation aims to provide gooddynamic wetting of aerosol droplets on surfaces upon application, thuspreventing paint cratering and other such problems. The formulation isshown below in Table 12.

TABLE 12 Component Function Weight % Surfactant 4 or 5 Wettingagent/flow 0.001-5    levelingagent/ slip control agent Gas propellentPropellant  5-30 Oil-in-water emulsion Pigmentation 0.1-25  Tamol 731ADispersant agent 1-4 Isopropanol (97-99% purity) Solvent/carrier  7-15Efka SI2022 or SI 2723 Anti-foaming agent 0.001-2    Water   19-86.9

Aspects

Aspect 1 is a compound of Formula I:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

n is an integer from 1 to 12;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, hydroxyl,and C₁-C₆ alkyl; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

Aspect 2 is the compound of Aspect 1 represented by Formula Ia:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

m is an integer from 1 to 6;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, and C₁-C₆alkyl wherein the alkyl chain is optionally substituted with one or moresubstituents selected from the group consisting of carboxyl,carboxylate, and sulfonate; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

Aspect 3 is the compound of either of Aspects 1 or 2 represented byFormula Ib:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate;

p is 5;

the terminal nitrogen is optionally further substituted with R³, whereinR³ is selected from the group consisting of hydrogen, oxygen, and C₁-C₆alkyl, wherein the alkyl chain is optionally substituted with one ormore substituents selected from the group consisting of carboxyl,carboxylate, and sulfonate; and

an optional counterion may be associated with the compound and, ifpresent, the counterion may be selected from the group consisting ofchloride, bromide, and iodide.

Aspect 4 is the compound of any of Aspects 1-3, wherein R¹ and R² aremethyl.

Aspect 5 is the compound of Aspect 1, wherein n is 5.

Aspect 6 is the compound of any of Aspects 1-5, wherein R³ is hydrogen.

Aspect 7 is the compound of any of Aspects 1-6, wherein the counterionis selected from the group consisting of chloride, bromide, and iodide.

Aspect 8 is the compound of Aspect 7, wherein the counterion ischloride.

Aspect 9 is the compound of any of Aspects 1-5, wherein R³ is methyl.

Aspect 10 is the compound of Aspect 9, wherein the counterion isselected from the group consisting of chloride, bromide and iodide.

Aspect 11 is the compound of Aspect 10, wherein the counterion isiodide.

Aspect 12 is the compound of any of Aspects 1-5 wherein R³ is an oxygenatom.

Aspect 13 is the compound of any of Aspects 1-5, wherein R³ is C₁-C₆alkyl substituted with a terminal sulfonate.

Aspect 14 is the compound of any of Aspects 1-3, wherein the compound is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexanamide,having the following formula:

Aspect 15 is the compound of any of Aspects 6-8, wherein the compound is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexaminiumchloride, having the following formula:

Aspect 15 is the compound of any of Aspects 9-11, wherein the compoundis 36-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N,N-trimethyl-6-oxohexan-1-aminiumiodide, having the following formula:

Aspect 17 is the compound of Aspect 12, wherein the compound is6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-amineoxide, having the following formula:

Aspect 18 is the compound of Aspect 13, wherein the compound is4-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)butane-1-sulfonate,having the following formula:

Aspect 19 is the compound of Aspect 13, wherein the compound is5-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)pentane-1-sulfonate,having the following formula:

The invention claimed is:
 1. A compound of Formula I:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate; n is an integer from 3to 12; the terminal nitrogen is optionally further substituted with R³,wherein R³ is selected from the group consisting of hydrogen, oxygen,hydroxyl, and C₁-C₆ alkyl; and an optional counterion associated withthe compound which, if present, is selected from the group consisting ofchloride, bromide, and iodide.
 2. The compound of claim 1, representedby Formula Ia:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate; m is an integer from 3to 6; the terminal nitrogen is optionally further substituted with R³,wherein R³ is selected from the group consisting of hydrogen, oxygen,and C₁-C₆ alkyl wherein the alkyl chain is optionally substituted withone or more substituents selected from the group consisting of carboxyl,carboxylate, and sulfonate; and an optional counterion associated withthe compound which, if present, is selected from the group consisting ofchloride, bromide, and iodide.
 3. The compound of claim 1, representedby the following Formula Ib:

wherein R¹ and R² may be the same or different, and comprise at leastone group selected from the group consisting of C₁-C₆ alkyl, optionallythe C₁-C₆ alkyl may include one or more of oxygen, nitrogen, or sulfuratoms or groups that include at least one of these atoms, and the alkylchain may be optionally substituted with one or more substituentsselected from the group consisting of hydroxyl, amino, amido, sulfonyl,sulfonate, carbonyl, carboxyl, and carboxylate; p is 5; the terminalnitrogen is optionally further substituted with R³, wherein R³ isselected from the group consisting of hydrogen, oxygen, and C₁-C₆ alkyl,wherein the alkyl chain is optionally substituted with one or moresubstituents selected from the group consisting of carboxyl,carboxylate, and sulfonate; and an optional counterion associated withthe compound which, if present, is selected from the group consisting ofchloride, bromide, and iodide.
 4. The compound of claim 1, wherein R¹and R² are methyl.
 5. The compound of claim 1, wherein n is
 5. 6. Thecompound of claim 5, wherein R³ is hydrogen.
 7. The compound of claim 6,wherein the counterion is selected from the group consisting ofchloride, bromide, and iodide.
 8. The compound of claim 7, wherein thecounterion is chloride.
 9. The compound of claim 5, wherein R³ ismethyl.
 10. The compound of claim 9, wherein the counterion is selectedfrom the group consisting of chloride, bromide, and iodide.
 11. Thecompound of claim 10, wherein the counterion is iodide.
 12. The compoundof claim 5, wherein R³ is an oxygen atom.
 13. The compound of claim 5,wherein R³ is C₁-C₆ alkyl, substituted with sulfonate.
 14. The compoundof claim 5, wherein the compound is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexanamide, having the followingformula:


15. The compound of claim 8, wherein the compound is6-(dimethylamino)-N-(3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)hexaminium chloride, having thefollowing formula:


16. The compound of claim 11, wherein the compound is 36-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N,N-trimethyl-6-oxohexan-1-aminiumiodide, having the following formula:


17. The compound of claim 12, wherein the compound is6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-amineoxide, having the following formula:


18. The compound of claim 13, wherein the compound is4-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)dimethylammonio)butane-1-sulfonate,having the following formula:


19. The compound of claim 13, wherien the compound is5-((6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino-6- oxohexyl)dimethylammonio)pentane-1-sulfonate, having thefollowing formula: